Convert Fahrenheit to Celsius

Temperature Conversion: Learn

The metric system uses the Celsius scale to measure temperature.
However, temperatures are still measured on the Fahrenheit scale in the U.S.

Water freezes at 0° Celsius and boils at 100° Celsius,
which is a difference of 100°. Water freezes at 32° Fahrenheit
and boils at 212° Fahrenheit, which is a difference of 180°.
Therefore each degree on the Fahrenheit scale is equal to 100/180 or 5/9 degrees on the Celsius scale.

How to convert Fahrenheit temperatures to Celsius:

Subtract 32° to adjust for the offset in the Fahrenheit scale.

Multiply the result by 5/9.

Example: Convert 98.6°F to Celsius

98.6 - 32 = 66.6

37 * 9/5 = 333/5 = 66.6

66.6 + 32 = 98.6°F

There is a mental math method to approximate the Fahrenheit to Celsius
conversion. The ratio of 5/9 is approximately equal to 0.55555....

How to approximately convert Fahrenheit temperatures to Celsius with mental math:

Subtract 32° to adjust for the offset in the Fahrenheit scale.

Divide the difference by 2 (multiply by 0.5)

Take one-tenth of that quotient (0.5 * 1/10 = 0.05) and add it to the quotient